纳米镍-铁去除四氯乙烯的影响因素

Factors affecting the dechlorination of perchloroethylene by nano-Ni/Fe

氯代烃是地下水中最常检出的有机污染物之一,传统的处理方法需要很长时间与大量经费。本文利用批实验的研究方法以四氯乙烯(PCE)为目标污染物,研究纳米镍铁在去除PCE过程中的影响因素。实验结果表明,暴露后的纳米镍铁脱氯速率比不暴露时速率降低约4倍;反应温度是影响反应速率的重要因素之一,每升高10℃,反应速率常数kSA提高2～3倍;在一定范围内,镍/铁质量比越高,越利于脱氯反应的快速进行,镍/铁的质量比为8%左右时,对氯代烃脱氯速率最快;反应液中的溶解氧不利于纳米颗粒对氯代烃的降解。

Chlorinated hydrocarbons are widely detected in groundwater, but the conventional methods for their removal are not economical both in time and in cost. This paper deals with the factors affecting the removal of PCE by nano-Ni/Fe. The data shows that the reaction rate of the unexposed nano-Ni/Fe is 4 times larger than the exposed one. Temperature is one of the important affecting factors. The reaction rate constant will increase by 2--3 times with the elevation of temperature by 10℃. Under certain conditions, the larger the percentage of Ni on the iron, the faster the dechlorination reaction. Nevertheless, 8 % is the best amount for dechlorination. Dissolved oxygen in solution is not helpful to the removal of chlorinated hydrocarbons.